This week was going to be a XC3090 which didn't pan out but heres at least something interesting as to why. First, the package was somewhat unusual in that its plastic and ceramic:
The F16600 block in the metal is glued or glass sealed on, not exactly sure which it was. In any case I carefully used a small butane torch and took it off with some pliers. Presumably as I was removing it a particle fell on the die. No big deal, I could just wash it off. I noticed a strange shine but didn't think too much of it at the time, dismissing it as a thick overglass or something. I washed it for a bid and the particle didn't come off. Finally I got a little more aggressive and took some lens tissue to it and it STILL wouldn't come off. Confused I put it under the microscope and poked at it. After a bit of poking:
I poked a hole in the gel covering the die. Its only on the die, not on the gold area. It surrounds the bond wires. Heres some grabbed with tweezers:
So other things came up and didn't get a die photo. I cleaned it with some RFNA (soaked fiberglass strip on top) which is probably done by now but didn't get a chance to clean and photograph it.